Business phones often have increased functionality compared with home phones or wireless (i.e. cellular) phones. For example, business phones can include the ability to connect multiple telephones together for a conference call, transfer incoming calls to another party, and create ring groups that allow a single call to ring to multiple extensions. The functionality has often been developed to increase productivity in business environments. The functionality has traditionally been provided by connecting business phones to private branch exchanges (PBXs).
As the use of mobile communication devices such as cell phones becomes omnipresent, the functionality of wired (fixed) business phones is converging to allow wireless phones to use the increased functionality traditionally offered by PBXs to fixed telephone systems.
Many mobile device manufacturers are designing dual mode phones that are capable of operating on carrier networks and private branch exchanges. For instance, a mobile device may be configured to operate using a Wimax connection to connect to a service provider's wireless network, while also operating through an Institute of Electrical and Electronics Engineers 802.11 “WiFi” standard to connect the mobile device to a business's private branch exchange server. The private branch exchange server can allow communication via Voice over Internet Protocol (VoIP), as well as the additional functionality afforded by PBXs.
As mobile device use in a business increases, there is a need to ensure the resiliency of the connection of a mobile device with the business's telecommunication system. Support for WiFi connected devices on the PBX side is not guaranteed and varies from vendor to vendor. Many VoIP protocols such as Session Initiation Protocol (SIP) rely on the Domain Name System (DNS) as the standard to provide resiliency.
The DNS standard requires a VoIP application operating on a mobile device to support DNS. DNS requires the use of timeouts to discover communication failures. Transmission protocols such as User Datagram Protocol (UDP) operate on a 32 second default timeout. However, this time period is typically too long for human interfaces. A person typically is not willing to wait for 32 seconds to determine if a telephone call is successful.
Reference will now be made to the exemplary embodiments illustrated, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended.